Phenoxy acetals and their utility as herbicides

ABSTRACT

Meta-phenoxy acetals having the formula   in which X is oxygen or sulfur, R and R1 are independently lower alkyl, R and R1 taken together are ethylene or trimethylene, R2 is alkyl, monocyclohexylamino, monoalkylamino, monoalkenylamino, dialkylamino, alkoxy, alkylthio, haloalkyl, substituted-phenyl wherein said substituents are methyl, monochloro or dichloro. The compounds are useful as herbicides.

United States Patent 1191 Teach [451 Sept. 2, 1975 PHENOXY ACETALS ANDTHEIR UTILITY AS HERBICIDES [75] inventor: Eugene G. Teach, El Cerrito.Calif.

[73] Assignee: Stauiier Chemical Company,

1 Westport, Conn.

221 Filed: Aug. a, 1913 211 Appl.1\1o.:385,507

Related U.S. Application Data [62] Division of Ser. No. 124.541. March15. 1971, Pat.

[52] U.S. Cl 260/5 53 A; 71/98; 7l/99; 71/100; 71/106; 71/118; 71/120;260/455 A,

260/471 C; 260/551 S; 260/558 P;

260/558 D; 260/552 R; 260/551 R; 260/562 R [51] Int. C13... C07C 127/15;CO7C 127/19 [58] Field of Search. 260/553 A, 552 R [56] References CitedUNITED STATES PATENTS 10/1953 Todd ..2e0/553x 12/1973 Teach ..260/553XPrimary Examiner-Howard T. Mars Assistant Examiner-C1. T. BreitensteinAttorney, Agent, or Firm-Harry A. Pacini; Daniel C. Block; Edwin H.Baker [57] ABSTRACT Meta-phenoxy aceta ls having the formula HC-R,

PHENOXY ACETALS AND THEIR UTILITY AS HERBICIDES This is a division ofapplication Serial No. 124,541, filed Mar. 15, 1971, now U.S. Pat. No.3,780,104.

This invention relates to certain novel amide and urea substitutedmeta-phenoxy acetals which are useful as herbicides. The compounds ofthe present invention are new compositions of matter and correspond tothe general formula in which X is oxygen or sulfur, R and R, areindependently lower alkyl, R and R l taken together are ethyl ene ortrimethylene, R is alkyl, monocyclohexylamino, monoalkylamino,monoalkenylamino, dialkylamino, alkoxy, alkylthio, haloalkyl,substituted-phenyl wherein said substituents are methyl, monochloro ordichloro.

In the above description, the following preferred embodiments areintended for the various substituent groups: for R and R lower alkylpreferably includes, unless otherwise provided for, those members whichcontain from 1 to 4 carbon atoms, inclusive, in both straight chain andbranched chain configurations, for example, methyl, ethyl, n-propyl,isopropyl, n-butyl, sec.-butyl and isobutyl; for R alkyl preferablyincludes those members which contain from 1 to 8 carbon atoms instraight and branched chain configurations, for example, methyl, ethyl,n-propyl, isopropyl, nbutyl, sec.-

butyl, amyl, isoamyl, n-hexyl, isohexyl, 2,4,4-

trimethylpentyl 1,1-di-methylbutyl, l-methylbutyl; the terms alkoxy andalkylthio, preferably includes those members of the groups which containfrom 1 to 6 car bon atoms, such as methoxy, ethoxy, propoxy, hexoxy,methylthio, ethylthio, propylthio and hexylthio and their isomers inbranch chanined configurations. The term haloalkyl preferably includesthose members of the group which contain 1 to 4 carbon atoms, inclusive,and mono, di, tri, tetra, and penta halogens, either the same or mixedof the group fluorine, chlorine and bromine. Preferably, fluorine andchlorine, such as monochloromethyl, dichloromethyl, trichloromethyl,monofluoromethyl, difluoromethyl, trifluoromethyl, chloro fluoromethyl,dichlorofluoromethyl, difluoro chloromethyl, chlorobromomethyl,dibromomethyl, monochloroethyl, 1,1-dichloroethyl, 1,2-

BrCH Ch (H ONu/DMF chlorofluoroethyl, 1,2-difluoroethyl,pentafluoroethyl, tetrachloromonofluoroethyl, l-monochloropropyl, 1,2-dichloro-1,2-difluoropropyl, monochlorobutyl, monofluorobutyl, andmonobrornobutyl and the like. The terms monoalkylamino and dialkylamino,preferably denote the groups H R N and N 4 R, \R,

respectively, in which R R and R independently are alkyl groups whichcontain 1 to 6 carbon atoms, inclusive, in either straight chain orbranched chain configurations, for example, methyl, ethyl, n-propyl,isopropyl, n-butyl, sec-butyl, amyl, isoamyl, n-hexyl and isohexyl. Theterm monoalkenylamino, preferably includes those members which contain 2to 4- carbon atoms, inclusive, that is, wherein the alkenyl substituentcontains at least one double bond and contains 2 to 4 carbon atoms,inclusive, such as vinyl, alkyl, propenyl-1 butenyl-l, butenyl-Z and thelike.

The compounds of this invention have been found to be active herbicidesof a general type. That is, certain members of the class have been foundto be herbicidally effective against a wide range of plant species. Amethod of controlling undesirable vegetation of the present inventioncomprises applying an herbicidally effective amount of theabove-described compounds to the area of plant locus where control isdesired.

An herbicide is used herein to mean a compound which controls ormodifies the growth of plants. By a growth controlling amount is meantan amount of compound which causes a modifying effect upon the growth ofplants. Such modifying effects include all deviations from naturaldevelopment, for example, killing, retardation, defoliation,desiccation, regulation, stunting, tillering stimulation, dwarfing andthe like. By plants" it is meant germinant seeds, emerging seedlings,and established vegetation, including the roots and above-groundportions.

The compounds of the present invention are pre pared by severaldifferent methods, depending upon the nature of the starting materialsand the products desired. For example, two preferred routes to obtainthe instant compounds are as follows. The acetaldehyde acetal group isintroduced into meta-aminophenol to yield a meta-amino acetalintermediate. This intermediate is further reacted with a suitable acidchloride, chloroformate or isocyanate to yield the desired substitutedanilide, carbanilate or urea phenoxy acetal, according to scheme 1.

in which X, R, R and R have the meanings given hereinabove. The reactionaccording to scheme 11 can also be employed wherein the meta-hydroxyanilide, carbanilate or urea is first prepared utilizing metaaminophenoland the suitable acid chloride, chloroformate or isocyanate. Theresulting m-hydroxy anilide, carbamate-or urea is treated with ahaloacetaldehyde acetal to yield the desired compounds of thisinvention.

in which X, R, R, and R have the meanings given hereinabove.

The reactions proceed readily in the liquid phase. The employment of asolvent is also useful, facilitating processing, as well as agitation ofthe reactants. Solvents such as acetone are conveniently employed. Thereactions are carried out at temperatures that permit operation in theliquid phase. The temperatures are between about room temperature andreflux temperature of the solvent, if a solvent is employed. in eachinstance, after the reaction is complete, the recovery of the product iscarried out by normal work-up procedures such as crystallization,sublimation or distillation.

The compounds of the present invention and their preparation are moreparticularly illustrated by the following examples. Following theexamples is a table of compounds which are prepared according to theprocedures described herein.

EXAMPLE I Preparation of Intermediate: m-aminophenoxyacetaldehydediethylacetal. m-Aminophenol, 109 g., is dissolved in 500ml. of dimethyl formamide and 216 g. of 25% sodium methoxide in methanolis added and the excess methanol stripped off under vacuum.Bromoacetaldehyde diethylacetal, 200 g., is added and the mixture heatedat reflux for 5 hours and then poured into water. The product is takenup in methylene chloride, washed with dilute base and water, dried overanhydrous magnesium sulfate and the solvent stripped under vacuum. Theyield of the title compound is 130 g., n 3 1.5151.

The dimethyl acetal is prepared similarly from chloroacetaldehydedimethylacetal.

EXAMPLE II Preparation of m-propionamidophenoxy.acetaldehydediethylacetal. Nine and nine-tenths ((9.9 g.) grams of3-hydroxy propionanilide is dissolved in 100 ml. of dimethylformamide,13 g. of 25% sodium methoxide in methanol is added. This is followed by1 1.8 g. of bromoacetaldehyde diethylacetal and the mixture is heated atreflux for 8 hours, stirred for an additional 16 hours and then pouredinto water. The product is taken up in methylene chloride, washed withdilute base and acid, dried over magnesium sulfate and the solventremoved under vacuum. The yield of the title compound is 9 g., n,,*"=1.5160.

OR BrCH CH EXAMPLE Ill Preparation of m-methylureidophenoxyacetaldehydedimethylacetal. Thirteen and eight-tenths 13.8 g.) grams ofm-aminophenoxy acetaldehydedimethylacetal is dissolved in 100 ml. ofacetone, 4.5 g. of methylisocyanate is added and the mixture heated atreflux for an hour. The solvent is stripped under vacuum. Tlggrgsisobtained 17.4 g. of the title compound, n,,""

OR OCH-CH EXAMPLE IV Preparation of m-propionamidophenoxyacetaldehydedimethylacetal. Thirteen and eight-tenths 13.8 g.) grams ofm-aminophenoxy acetaldehydedimethylacetal is dissolved in g. of acetoneand 7.5 g. of triethylamine and 6.6 g. of propionylchloride is addedportionwise with cooling and stirring. The mixture is poured into water,the product taken up in methylene chloride, dried over magnesium sulfateand the solvent stripped under vacuum. The yield of the title compoundis 15.9 g., n, 1.5220.

EXAMPLE V Preparation of m-S-methylthiocarbamylphenoxyacetaldehydediethylacetal. Eleven and three-tenths (11.3 g.) grams ofm-aminophenoxy acetaldehydediethylacetal is dissolved in 100 ml. ofacetone and 6.5 g. of triethylamine. The mixture is cooled in a waterbath and 6.7 g. of methyl chlorothioformate is added portionwise. Afteraddition is complete, the mixture is poured into approximately 500 ml.of water and the product taken up with methylene chloride, dried overmagnesium sulfate and the solvent removed under vacuum. The yield of thetitle compound is 12 g., n,, 1.5355.

The following is a table of the illustrative compounds which areprepared according to the aforementioned procedures. Compound numbershave been assigned to them and are used for identification throughoutthe balance of the specification.

HERBICIDAL SCREENING TESTS As previously mentioned, the herein-describedcompounds produced in the above-described manner are phytotoxiccompounds which are useful and valuable in controlling various plantspecies. Compounds of this invention are tested as herbicides in thefollowing manner.

Pre-emergence herbicide test. On the day preceding treatment, seeds ofseven different weed species are planted in individual rows using onespecies per row across the width of the flat. The seeds used are hairycrabgrass (Digital-isanguinalir (L.) Scop. yellow foxtail (Setariuglauc'u (L.) Beauv.), watergrass (EC/linuclilou crusgalli (L.) Beauv.),California red oat (Arena sutiva (L.)), redroot pigweed (Amaranthusrelroflexus (L.)). lndian mustard (Brussit-ujuncea (L.) Coss.) and curlydock (Rumex crirpus (L.)). Ampleseeds are planted to give about 20 to 50seedlings per row, after emergence, depending on the size of the plants.The

flats are watered after planting. The spraying solution is prepared bydissolving 50 mg. of the test compound in 3 ml. of a solvent, such asacetone, containing 1% Tween 20 (polyoxyethylene sorbitan monolaurate).The following day each flat is sprayed at the rate of 20 pounds of thecandidate compound per 80 gallons of solution per acre. An atomizer isused to spray the solution onto the soil surface. The flats are placedin a greenhouse at 80F. and watered regularly. 2 weeks later the degreeof weed control is determined by comparing the amount of germination andgrowth of each weed in the treated flats with weeds in several untreatedcontrol flats. The rating system is as follows:

0 no significant injury (approximately O-l0 per cent control) 3 slightinjury (approximately 10-40 per cent control) 6 moderate injury(approximately 40-70 per cent control) 9 severe injury or death(approximately -100 per cent control) An activity index is used torepresent the total activity on all seven weed species. The activityindex is the sum of the numbers divided by 3, so that an activity indexof 21 represents complete control of all seven weeds. The results ofthis test are reported in Table II.

Post-emergence herbicide test. Seeds of five weed species, includinghairy crabgrass, watergrass, California red oats, lndian mustard, andcurly dock and one crop, pinto beans (Phaseulus vulgaris), are plantedin flats are described above for pre-emergence screening. The flats areplaced in the greenhouse at 7285F. and watered daily with a sprinkler.About 10 to 14 days after planting, when the primary leaves of the beanplant are almost fully expanded and the first trifoliate leaves are juststarting to form, the plants are sprayed. The spray is prepared byweighing out 50 mg. of the test compound, dissolving it in 5 ml. ofacetone containing 1% Tween 20 (polyoxyethylene sorbitan monolaurate)and then adding 5 ml. of water. The solution is sprayed on the foliageusing an atomizer. The spray concentration is 0.5% and the rate would beapproximately 20 lb/acre if all of the spray were retained on the plantand the soil, but some spray is lost, so his estimated that theapplieation rate is approximately 12.5 lb/acre.

Beans are used to detect defoliants and plant growth regulators. Thebeans are trimmed to two or three plants per flat by cutting off theexcess weaker plants several days before treatment. The treated plantsare placed back in the greenhouse and care is taken to avoid sprinklingthe treated foliage with water for three days after treatment. Water isapplied to the soil by means of a slow stream from a watering hose,taking care not to wet the foliage.

Injury rates are recorded 14 days after treatment.

The rating system is the same as described above for the pro-emergencetest where (O), (3), (6), and (9) are used for the different rates ofinjury and control. The injury symptoms are also recorded. The maximumactivity index for complete control of all the species in thepostemergence screening test is 18. This index represents the sum of therating numbers obtained with the six plant species used in the testdivided by 3. The herbicide activity index is shown in Table ll.

TABLE 11 HERBICIDAL ACTIVITY SCREENING RESULTS HERBICIDAL ACTIVITYINDEX** COMPOUND Pre-emcrgence Post-emergence NUMBER (2(1lb/A) (12.5lh/A) 2 18 17 3 13 15 4 17 18 5 l4 l8 6 18 18 7 19 18 8 17 '17 9 18 1810 6 13 11 10 17 12 17 17 13 19 17 14 19 18 15 21 18 v 17 18 17 19 18 1812 15 19 l9 18 20 7 ll 21 9 15 22 14 15 23 16 18 24 7 14 25 10 16 2 6 1527 9 18 8 9 15 29 4 14 3t) 0 4 31 0 7 32 3 11 **21 7()-l007( control ofall seven plant species tested pre-emergence. 18 70-10071 control of allsix plant species tested post-emergence.

The compounds of the present invention are used as pre-emergence orpost-emergence herbicides and are applied in a variety of ways atvarious concentrations. In practice, the compounds are formulated withan inert carrier, utilizing methods well-known to those skilled in theart, thereby making them suitable for application as dusts, sprays, ordrenches and the like, in the form and manner required. The mixtures canbe dispersed in water with the aid of a wetting agent or they can beemployed in organic liquid compositions, oil and water, water in oilemulsions, with or without the addition of wetting, dispersing oremulsifying agents. An herbicidally effective amount depends upon thenature of the seeds or plants to be controlled and the rate ofapplication varies from 1 to approximately 50 pounds per acre.

The phytotoxic compositions of this invention employing an herbicidallyeffective amount of the compounds described herein are applied to theplants in the conventional manner. Thus, the dust and liquidcompositions can be applied tothe plant by the use of powerdusters, boomand hand sprayers and spray-dusters. The compositions can also beapplied from airplanes as a dust or a spray because they are effectivein very low dosages. In order to modify or control growth of germinatingseeds or emerging seedlings, as a typical example, the dust and liquidcompositions are applied to the soil according to conventional methodsand are distributed in the soil to a depth of at least one-half inchbelow the soil surface. It is not necessary that the phytotoxiccompositions be admixed with the soil particles,

since these compositions can be applied merely by spraying or sprinklingthe surface of the soil. The phytotoxic compositions of this inventioncan also be applied by addition to irrigation water supplied to thefield to be treated. This method of application permits the penetrationof the compositions into the soil as the water is absorbed therein. Dustcompositions, granular compositions or liquid formulations applied tothe surface of the soil can be distributed below the surface of the soilby conventional means such as discing, dragging or mixing operations.

The phytotoxic compositions of this invention can also contain otheradditaments, for example, fertilizers, pesticides and the like, used asadjuvant or in combination with any of the above-described adjuvants.Other phytotoxic compounds useful in combination with theabove-described compounds include, for example,2,4-dichlorophenoxyacetic acids, 2,4,5-trichlorophenoxyacetic acid,2-methyl-4-chlorophenoxy-acetic acid and the salts, esters and amidesthereof; triazine derivatives, such as 2,4-bis(3-methoxypropylamino)-6-methylthio-S-triazine;2-chloro-4-ethylamino-6-isopropylamino-S-triazine, and 2-ethylamino-4-isopropylamino-6-methylmercapto-S-triazine, urea derivatives, such as3-(3,4-dichlorophenyl)-1,1-dimethyl urea and3-(p-chlorophenyl)-1,l-dimethyl urea and acetamides such asN,N-diallyla-chloroacetamide, and the like; benzoic acids such as3-amino-2,5- dichlorobenzoic; and thiocarbamates, such as S-propyldipropylthiocarbamate; S-ethyl-dipropylthiocarbamate,S-ethyl-cyclohexyl-ethylthiocarbamate, S-ethylhexahydro-ll-I-azepine-l-carbothioate and the like. Fertilizers usefulin combination with the active ingredients include, for example,ammonium nitrate, urea and superphosphate. Other useful additamentsinclude materials in which plant organisms take root and grow, such ascompost, manure, humus, sand and the like.

The concentration of a compound of the present invention, constitutingan effective amount in the best mode of administration in the utilitydisclosed, is readily determinable by those skilled in the art.

Various changes and modifications are possible without departing fromthe spirit and scope of the invention described herein and will beapparent to those skilled in the art to which it pertains. It isaccordingly intended that the present invention shall only be limited bythe scope of the claims.

What is claimed is:

1. A compound having the formula Mic-R II x in which X is oxygen; R andR, are independently lower alkyl; R is monocyclohexylamino,monoalkylamino, monoalkenylamino, or dialkylamino.

2. A compound according to claim 1 in which R, is monoalkylamino.

3. A compound according to claim 2 in which R and R, are each ethyl andR is methylamino.

4. A compound according to claim 2 in which R and R, are each ethyl andR is ethylamino.

5. A compound according to claim 2 in which R and R, are each ethyl andR is n-butylamino.

9 6. A compound according to claim 2 in which R and 9. A compoundaccording to claim 8 in which R and are each methyl and mctllylamlno' Rare each ethyl and R is dimethylamino.

A compound accordmg, to clam 2 l whlch R and 10. A compound according toclaim 8 in which R and are each methyl and n'butylamlflo' R, are eachmethyl and R is dimethylamino.

,8. A compound according to claim 1 m which R is 5 dialkylamino.

1. A COMPOUND HAVING THE FORMULA
 2. A compound according to claim 1 inwhich R2 is monoalkylamino.
 3. A compound according to claim 2 in whichR and R1 are each ethyl and R2 is methylamino.
 4. A compound accordingto claim 2 in which R and R1 are each ethyl and R2 is ethylamino.
 5. Acompound according to claim 2 in which R and R1 are each ethyl and R2 isn-butylamino.
 6. A compound according to claim 2 in which R and R1 areeach methyl and R2 is methylamino.
 7. A compound according to claim 2 inwhich R and R1 are each methyl and R2 is n-butylamino.
 8. A compoundaccording to claim 1 in which R2 is dialkylamino.
 9. A compoundaccording to claim 8 in which R and R1 are each ethyl and R2 isdimethylamino.
 10. A compound according to claim 8 in which R and R1 areeach methyl and R2 is dimethylamino.